‘How should I know?’ Decimus had sounded irritated at the intransigence of Clemens. ‘The road to freedom is always open, so the philosophers say.’

‘Lucretia killed herself,’ Valens said. ‘Her husband and family begged her not to, but she did.’

Everyone knew the story. Raped by the son of the last King of Rome, her suicide had been the catalyst for the overthrow of the monarchy. Her resolution had brought freedom to Rome, and left her name as a symbol of female courage.

‘Like I said,’ Decimus concluded, ‘it is in their nature.’

The other men lit a fire and prepared a meal. They used the last of the fresh meat and a portion of the onions and peas they had bought in Nineveh to make a stew. The flatbread had gone stale, so some of the men heated it on sticks in the fire.

Valens had taken two bowls and a flask of watered wine over to where the woman sat in the shade of a palm tree. The sun was almost directly overhead.

She looked at the food and drink and him equally without interest.

‘Eat,’ he said.

Mechanically she had done as she was told. She was wearing a white tunic someone must have given her. It was unbelted. That was one road to freedom closed. No danger of her hanging or strangling herself.

‘You speak Greek?’

She had nodded.

‘What is your name?’

‘Lucia, but I am also known as Al-zabba.’

‘Where are you from?’

‘Matiane.’

‘And what brought you here to the desert?’

‘Greed.’ Her reply was flat.

‘The dead man was your husband?’

She had said nothing.

‘The other a slave?’

‘I knew it was too dangerous, begged him not to.’

‘Your husband was trading wine to the nomads?’

‘He said they would pay high prices.’

‘They have none of their own.’

‘I told him they could not be trusted.’ There was an edge of desperation in her voice, an echo of that futile argument. ‘He would not believe that they would just take what they wanted.’

An old fable came into Valens’s mind. ‘The god Hermes was driving across the world in a chariot filled with lies, villainy and fraud. To every people he distributed a little of his cargo. In the desert the chariot broke, and the Arabs stole the remainder of the contents.’

She inclined her head sadly, as if he had done more than repeat a story his nurse had told him.

‘Where will you go?’

She’d drawn a shuddering breath, mastered herself. ‘Home to Matiane. If I can get there, if the gods relent. I have family there. If no one knows what has happened, our customs ensure that I will be given another husband.’

‘It was not your fault.’

‘That makes no difference. Would you marry a woman who had been defiled by the tent-dwellers?’

There had been nothing he could say.